When I take mine out for the winter, I coat it with petroleum jelly. Never thought to do this to a new impellor being saved as a spare.

 

Petroleum products can attack the rubber. If you want to store it in something, use olive oil or silicone grease.

 

Don't know about storage, I just store mine as it comes and they always seem to work fine. I would guess the overheat buzzer would have gone off for the mechanics. Although I was talking to someone at my boat yesterday meanwhile his was overheating and buzzing away and it was directly in front of mine and neither of us heard it...so you never know.

Anyway, I made a large laminated tag that I snap to the ignition key that says open seacock. I snap it on whenever I close the valve for whatever reason. It's mainly for myself but it also serves for purposes such as this. Just a thought.

 

You also have to wonder how long that impeller has been 'on the shelf' at the vendor. I do suspect that these bits can 'dry out' in time and become somewhat more brittle than they were when new. I think the same applies to other rubber parts like heat exchanger boots etc.

 

I had the same results with an impeller, luckily all rubber parts ended up before the heat exchanger. I suggest using either glycerin or talcum powder for spare storage, and/or vacuumpack individually.
I also had the same problems with belts. I went through two belts in one day, that were stored on board for over a year. They both delaminated.

 

We keep two spares (not in the engine compartment which get too hot!). I wipe our newly purchased spare down with the glycerin tab that comes with the impeller, wrap it in wax paper and vacuum seal it in a plastic pouch with our FoodSaver and put the date on the pouch with a marker. We replace the impeller at 100 hour intervals, or one year, whichever comes first, with the oldest spare and buy a new one. Never had a failure.

As others have noted, do not use a petroleum based lube.

FWIW...

 

I practice the rotating inventory method exactly and replace the impeller at least annually. Always during Spring commissioning and again if hours suggest. The only other I've ever had fail was many many years ago, when I was less diligent. I've never had a brand new one fail, although, I have heard of it happening.

I am also suspect of the age of the impeller when I received it. How would one know.

I would rather not use the included glycerin pack for storage, as I would like to use it when it comes time to install. I particularly like to squeeze it right between the blades, after its been installed, to insure a seal for priming.

Spray with silicon spray maybe?

 

I would rather not use the included glycerin pack for storage, as I would like to use it when it comes time to install. I particularly like to squeeze it right between the blades, after its been installed, to insure a seal for priming. Spray with silicon spray maybe?

Or just walk into a CVS Pharmacy and pick up a little 3oz bottle of glycerine for a couple bucks and be set for life. That's what I did when I finally replaced my nearly impossible to reach and impossible to see impeller on my Yanmar after 6 years with no problems...... and although I know I cracked one vane with needle nose on extraction there was another cracked vane that may or may not have been cracked before I had to muscle it out with needle nose pliers. I also wasted a couple hours replacing the perfectly good impeller that has been cooling my Fisher Panda generator for the last 6 years. Back when all I had to do was kneel down in front of my previous engines and simply remove them I used to change every year or two. Now that it is major surgery I'll do it when I get around to it. Definitely NOT giving advise just telling my story.

 

EVOO works great.

 

I've heard of the idea. Sounds pretty weird and worry that the food oil goes rancid.

 

EVOO ... got me on that one! I thought it was EVil gOO ... but after gOOgling it I found out it has something to do with Extra Virgins.

 

If virgins always have spare impellers on them, I've learned something.

Hate the term EVOO by the way, reminds me of Rachel Ray. Ugh.

As far as the practical advice, is anything other than the cheapest olive oil really necessary?

 

I have noticed rubber products (tires, belts, hoses, shoes) made today seem to dry rot faster than stuff made 20 years ago. Maybe cheaper rubber compounds are being used, or more ozone in the atmosphere.

In any case, for belts and pump impellers may be a good idea to check for flexibility and cracking prior to installation. For the impeller bend the vane back and look for small cracks. For a belt, bend it and look for cracks. You can usually tell if a rubber is getting dry rot by look and feel.

 

Rubber stores best in powder, either talc, or cornstarch. Works well for nickel plated fish hooks, etc ,too.

 

Plus 1 for what Brent said - elastomer impellers (many call them "rubber", but they can be many different materials) are best kept dry, cool and OUT OF SUNLIGHT! The very process used to manufacture "rubber" impellers will keep the material curing, so they all will ultimately become brittle over time. The trick, as many here have said is to rotate stock (first in,first out) - but it is hard to tell how long a part has sat on the retailers shelf? Keep 'em dry, keep 'em cool and keep 'em out of UV light.

 

Agree with Brent, an old diving trick is to coat anything rubber based to keep it flexible is to smother it with talc powder, cheap and it works.

Mike

 

I will just add more of the same.

I change every year, sometimes 2 times a year, and at 100 hours whichever comes first.

I just take the old one off and throw it in a plastic bag and keep it until the next on comes off to replace it. I have never had a problem.

WHen buying a impeller, see if you can go to a large authorized dealer (Yanmar in my case) where they go through a lot of product. I was surprised that the prices were reasonable too (compared to WM).

I am not sure the key is what to store it in, I think the key is how often you rotate.

Lastly, I use dish soap when putting in my impeller. Easy, quick and available.

Just what I do...

Brian

PS I don't keep anything near the engine. All is in a cool area in storage in boat.

 

Concerning changing your impeller. I also purchase a water pump gasket. Should the gasket be coated with a sealer prior to installing? Like the gasket material in a tube you buy at the auto parts store. Or do you just install the gasket as it comes out of the package? Seems the gasket is like paper.

 

Make it up dry - right out of the package - with the pump housing and cover inside surface clean as possible. The gasket is "like paper" for a reason - to minimize axial leakage past the impeller. You don't want to goop up that joint and increase that clearance.

 

Ordinary silicone spray will preserve most rubber impellers forever, well at least 5 years if they're in a sealed container. Most are manufactured from gum rubber, and they will eventually dry out. However, in your case I suspect someone at the marina ran it dry--no doubt about it.

It takes a lot of wear to kill an impeller, even one used exclusively in salt water. Most outboard motor impellers will last 5 years when used a lot more than 100 hours--more if the engine is flushed with freshwater after each use. I had a 1957, 18.5 HP, Evinrude, Outboard motor that was still running great in 2001 and never had an impeller replacement performed.

Cheers,

Gary

 

Agree with that - but with one consolation: When you finally do replace it (assuming you do it before it ends up in the HE), getting it off can be a major PITA. Consistent replacement makes it an easy job.

Just my opinions.

Brian

 

Yep, I agree. Regular replacement sometimes saves lots of grief. For about 7 years of my younger life I owned an outdoor store that sold boats, motors, trailers, fishing tackle, etc... Part of the requirements to be an outboard motor dealer was that you had to service what you sold. OMC, at the time, had a huge assortment of highly specialized tools, one of which was a special puller for water pump impellers--it was the best thing since sliced bread when it came to removing corroded impellers from outboard lower units and inboard/outboard engines. Without that tiny puller I doubt that some of the impellers would have ever come out of the housings.

Cheers,

Gary

 

Great ideas, thank you. Silicon spray and a baggie or vacpac, take them out of the engine room is probably my plan. Can always use some silicon spray, I don't think I have any. The gnawing part is that this has never been a problem before.

I still think they ran the impeller dry when changing the fuel filters. When the Manager described his conversation with the tech, he claimed he had two reasons to believe his response. First, there was a second guy who corroborated his story (they are buddies afterall). Second, he said we were the only boat in the marina that closed their seawater thru hull, so they were very aware of it. One would think the second point would be exactly how they would miss opening it, and I still think it was the case. I'm going to start a new thread to see how many people close seacocks when they leave their boat for extended periods.

Here is a pic of the impeller. As I said originally, it was installed two weeks ago and run for about an hour prior to this failure. It was purchased about 9 months ago.

 

Great ideas, thank you. Silicon spray and a baggie or vacpac, take them out of the engine room is probably my plan. Can always use some silicon spray, I don't think I have any. The gnawing part is that this has never been a problem before.

I still think they ran the impeller dry when changing the fuel filters. When the Manager described his conversation with the tech, he claimed he had two reasons to believe his response. First, there was a second guy who corroborated his story (they are buddies afterall). Second, he said we were the only boat in the marina that closed their seawater thru hull, so they were very aware of it. One would think the second point would be exactly how they would miss opening it, and I still think it was the case. I'm going to start a new thread to see how many people close seacocks when they leave their boat for extended periods.

Here is a pic of the impeller. As I said originally, it was installed two weeks ago and run for about an hour prior to this failure. It was purchased about 9 months ago.

View attachment 10989

They ran it dry or did not properly make sure it was making water before starting (or, when you installed, you did not make sure it was making water first before running). I have always heard it takes circa two minutes to screw one of those up... but that is just hearsay.

Brian

 

Judging by the photo, I would say it was run dry, got very hot and ripped off the one impeller blade, cracked a couple others. You can fry an impeller blade with a dry run in less than 30 seconds--that's all it takes to destroy one.

Good Luck,

Gary

 

I have accidently run some impellers dry (forgot to open seacock) to the point the engine overheat alarm came on. After inspecting the impellers they looked good as new and kept operating for many miles. These were yanmar impellers. Maybe the yard is telling the truth. Maybe the rubber was just dry rotted.